LTS Refresh: Merge release-R121-cos-6.6 up to 8efce2be551b

BUG=b/553150597
TEST=presubmit
RELEASE_NOTE=LTS Refresh from main-R121-cos-6.6 to release-R121-cos-6.6

cos-patch: lts-refresh
Change-Id: I537e60f11ef72111b17543f691b716ae2c07cdb2
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/190426
Reviewed-by: Kevin Berry <kpberry@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>